package it.flaminiandrea.jphonesms.util.encryption;

import it.flaminiandrea.jphonesms.logger.RuntimeLogger;

import java.security.MessageDigest;

import javax.swing.JOptionPane;

import org.apache.log4j.Logger;

public class SHA1Encrypter {

	public static String SHA1(String text)  { 
		try {
			MessageDigest md;
			md = MessageDigest.getInstance("SHA-1");
			byte[] sha1hash = new byte[40];
			md.update(text.getBytes("iso-8859-1"), 0, text.length());
			sha1hash = md.digest();
			return convertToHex(sha1hash);
		} catch (Exception e) {
			Logger logger = RuntimeLogger.getInstance().getLogger(SHA1Encrypter.class);
			logger.error("Error in the encryption function.", e);
			JOptionPane.showMessageDialog(null, e.getMessage(), "Error!", 0);
		}
		return null;
	}

	private static String convertToHex(byte[] data) { 
		StringBuffer buf = new StringBuffer();
		for (int i = 0; i < data.length; i++) { 
			int halfbyte = (data[i] >>> 4) & 0x0F;
			int two_halfs = 0;
			do { 
				if ((0 <= halfbyte) && (halfbyte <= 9)) 
					buf.append((char) ('0' + halfbyte));
				else 
					buf.append((char) ('a' + (halfbyte - 10)));
				halfbyte = data[i] & 0x0F;
			} while(two_halfs++ < 1);
		} 
		return buf.toString();
	} 

}
